Carburetor



May 29, 1928. 1,671,288

G. M. HOLLIEY GARBURETOR Original Filed May 18, 1921.

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Patented May 29, 1928.

UNITED STATES PATENT OFFICE.

GEORGE M. HOLLEY, 0F DETROIT, MICHIGAN.

CARBURETOR.

Application iled May 18, 1921, Serial No. 470,493. Renewed December 16,1927.

My invention relates specifically to a carburetor having a main air andprimary air passages in which the main air is mechanically controlled bya throttle which also controls the primary air.

Figure l shows a longitudinal sectional elevation of a horizontalcarburetor.

Figure 2 shows the throttle control isolated from the carburetor for thepurposes of illustration.

Figure 3 shows a transversesectional end View on the plane X-Y of Figure1 of the primary air throttle as it stands with relation to the primaryair passage in a Wide open position of the throttle.

Figure 4 is a' corresponding view in the closed position of thethrottle.

Figure l shows at A an air entrance to the carburetor controlled by theusual choke valve B; the air passage passes by the main air throttle Cand through the venturi D to the carburetor exit M. Adjacent to andbelow the main air passage A-M is the auxiliary primary air passage EEinto which pro]ects the nozzle F controlled by the adjustable needle Gr.The main air throttle C is carried by a throttle rod J, the hollow endof which K projects into the passage EE. This hollow extension Kreceives the nozzle F and has two opposite pairs of ports. 'llhese twopairs of ports register with the passage EE so that on moving thethrottle 'C ,the extension valve K, entrance passage E and the exitpassage E are suitably restricted to correspond with the given positionof the throttle C. Y

Fuel is supplied to the main nozzle F `through the float chamber H whichmaintains the fuel at a constant level in the vicinity of the top ofth`e fuel nozzle F. The throttle rod J is controlled by the throttlelever L.

The main air passage AM, the auxiliary passage EE and the fuel nozzle Fare all carried in one casting P to which is secured the float bowl Q.

Mode of operation.

proportion of air to fuel is regulated by the proportions of the portsC0 and NN in the extension K of the throttle rod J and also the angle towhich the axes of the said ports bear to the throttle plate C. Theproportions and angles of these ports as shown y time the port N isrestricted thus cutting down the supply of fuel.

On turning the throttle to the fully closed position shownin Figure 4,the small port O has taken the place of the port N and the large port Oreduces the suction on the fuel nozzle F to such a point that only theminimum supply of fuel is furnished that is required to idle the engine.

Claims:

l. A carburetor having a main air passage leading to a venturi, anadditional air passage eommunicating at one end withthe main air passageand at the other end with said venturi, a fuel nozzle positioned Withinsaid additional air passage intermediate the ends of the additional airpassage, whereby a mixture of fuel and air is delivered to said barrelthrottle located in said additional air passage, said fuel nozzleprojecting within the confines of said barrel throttle, a plurality ofpairs of ports of diderent relativo capacities in said barrel throttleat a point substantially in alignment with the upper extremity of thefuel nozzle, one pair of ports serving at high speed and the other pairof ports serving at low speeds, a throttle valve in the main air passageand secured to said throttle rod, wherebv the barrel throttle and thethrottle valve in said main air passage are operated together to supplya substantially constant fuel ratio to the said venturi.

l 2. A carburetor having a main air passage leading to a venturi, anadditional air passage comlnunicating at one end with the main airpassage and at the other end with said venturi, a fuel nozzle positionedwithin said additional air passage intermediate the ends of" theadditional air passage, whereby a mixture of fuel and air is deliveredto said venturi, a hollow throttle rod extending through said main airpassage and 'provided with a barrel throttle located in Said additionalair passage, said fuel nozzle projecting within the confines of thebarrel throttle, said barrel throttle being provided with a plurality ofpairs of ports of different relative capacities to control the admissiono't' air to and from the said fuel nozzle, said ports being insubstantial alignment with the upper extremity of the fuel nozzle, onepair of the ports serving at high speed and t-he other pair serving atlow speed, a throttle valve in the main air passage and secured to thethrottle rod, a needle valve positioned within said hollow throttle rodand screwthreaded1y connected therewith, said needle valve cooperatingat its lower extremity-with the fuel nozzle, said barrel throttle,needle valve, and throttle in the main passage being operated togetherto thereby secure a substantially con-V stant fuel ratio mixture.

3. A carburetor having a main air passage leading to a venturi, anadditional air passage communicating at one end with the main airpassage and at the other end with said venturi, a fuel nozzle positionedwithin said additional air passage intermediate the ends of theadditional air passage, whereby a mixture of fuel and air is deliveredto said venturi, a throttle rod extending through said main air passageand provided with a barrel throttle located in said additional airpassage, said fuel nozzle projecting within the confines of said-barrelthrottle, a plurality of pairs of ports of different relative capacitiesin said barrel throttle at a point substantially in alignment with theupper extremity of the fuel nozzle, one pair of ports serving at highspeed and the other pair of ports serving at low speed, a throttle valvein the main air passagek and secured to Said throttle rod, whereby thebarrel thro-t'- tle and the throttle in said additional air passage areoperated together to supply a substantially constant fuel ratio to thesaid venturi, a 4choke valve located in the main air passage at a pointin advance of the end of the additional air passage communicating withthe main air passage, said choke valve serving, when closed, to shut offthe a'ir n vpassing through the main air passage and divert the airthrough the additional air passage to the fuel nozzle to deliver a richmixture to the Venturi tube when starting.

In testimony whereof I affix my signature.

GEO. M. HOLLEY.

